University at Buffalo researchers studied all auto crashes involving a fatality in the U.S. between 2000 and 2003 where someone occupied the rear middle-seat. They found that occupants of the back seat are 59 percent to 86 percent safer than passengers in the front seat and that, in the back seat, the person in the middle is 25 percent safer than other back-seat passengers.

"After controlling for factors such as restraint use, vehicle type, vehicle weight, occupant age, weather and light conditions, air-bag deployment, drug results and fatalities per crash, the rear middle seat is still 16 percent safer than any other seat in the vehicle," said Dietrich Jehle, M.D., UB associate professor of emergency medicine and lead author.

Jehle and colleagues at the Center for Transportation Injury Research (CenTIR), conducted a retrospective cohort study of fatal crashes in which there were rear-seat occupants and at least one fatality in the vehicle. Nearly half of the passengers in the back seat - 46.9 percent - were not wearing seat belts, results showed, and of these unrestrained passengers, 34.6 percent were fatally injured, compared to only 14.9 percent of seat-belt wearers. In general, back-seat passengers who wore seat belts were 2.4 to 3.2 times more likely to survive a crash than their unbelted back-seat companions.

One reason the rear middle seat is the safest, Jehle noted, is because passengers sitting in this position have a much larger "crush zone" than rear side-seat passengers in near-side impact crashes. The crush zone is an area of the car designed to collapse in an effort to absorb some of the impact from a collision. "In addition, in rollover crashes there is potentially less rotational force exerted on the middle seat passenger than on those in the window seats," he said.